Citrulline-containing beverage

ABSTRACT

The invention provides an easy-to-drink beverage that contains citrulline, wherein the generation of bad odors due to storage or heating is suppressed. In particular, the invention provides a beverage that contains citrulline and citric acid, as well as sodium citrate or disodium hydrogen phosphate.

TECHNICAL FIELD

The present invention relates to a beverage containing citrulline andcitric acid, as well as sodium citrate or disodium hydrogen phosphate.

BACKGROUND ART

Citrulline, not an amino acid that constitutes a protein in a livingorganism, is one of the intermediates in the urea cycle, and is producedfrom arginine along with nitrogen oxide (NO), which is known as asubstance possessing vasodilating action, and is condensed with asparticacid and regenerated into arginine. Citrulline is known to exhibituseful actions such as ammonia metabolism promotion (Non-patent Document1), blood flow improvement by vasodilation (Non-patent Document 2),blood pressure reduction (Non-patent Document 3), neurotransmission(Non-patent Document 4), immunopotentiation (Non-patent Document 5), andactive oxygen elimination (Patent Document 1). For this reason, with theexpectation for these actions, it is common practice to take citrullinein the form of pharmaceuticals, functional foods and the like.

It is known that in aqueous solutions of basic amino acids such aslysine, arginine, ornithine, hydroxylysine, and histidine, bad odors aregenerated due to storage or heating, and that the bad odors aresuppressed by adding a water-soluble reducing agent and a chelatingagent to the aqueous solutions (Patent Document 2).

-   patent document 1: JP-A-2002-226370-   patent document 2: JP-A-5-246962-   non-patent document 1: Cell Biochemistry & Function, 2003, vol.    21, p. 85-91-   non-patent document 2: European Journal of Pharmacology, 2001, vol.    431, p. 61-69-   non-patent document 3: Journal of Clinical Investigation, 1991, vol.    88, p. 1559-1567-   non-patent document 4: Gastroenterology, 1997, vol. 112, p.    1250-1259-   non-patent document 5: The journal of biological chemistry, 1994,    vol. 269, p. 9405-9408

DISCLOSURE OF THE INVENTION Problems to Be Solved by the Invention

There is a demand for the development of an easy-to-drink beverage thatcontains citrulline, wherein the generation of bad odors due to storageor heating is suppressed.

Means for Solving the Problems

The present inventors extensively investigated to solve theabove-described problems, found that by allowing citric acid and sodiumcitrate, or citric acid and disodium hydrogen phosphate, to be presentin a beverage that contains citrulline, the generation of bad odors dueto storage or heating is suppressed, and have developed the presentinvention.

Accordingly, the present invention relates to the following (1) to (5).

(1) A beverage containing citrulline and citric acid, as well as sodiumcitrate or disodium hydrogen phosphate.

(2) The beverage according to (1) above, wherein the citrullineconcentration is 0.01 to 2% by weight.

(3) The beverage according to (1) or (2) above, wherein the blendingratio by weight of citric acid and sodium citrate is 5:1 to 1:6, and thecombined concentration of citric acid and sodium citrate is 0.01 to 3%by weight.

(4) The beverage according to (1) or (2) above, wherein the blendingratio by weight of citric acid and disodium hydrogen phosphate is 3:1 to1:5, and the combined concentration of citric acid and disodium hydrogenphosphate is 0.01 to 4% by weight.

(5) The beverage according to any of (1) to (4) above, wherein the pH is2 to 7.

Advantages

According to the present invention, it is possible to provide aneasy-to-drink beverage that contains citrulline, wherein the generationof bad odors due to storage or heating is suppressed.

BEST MODE FOR CARRYING OUT THE INVENTION

As the citrulline used in the present invention, L-citrulline andD-citrulline can be mentioned, with preference given to L-citrulline.

Citrulline can be acquired by a method based on chemical synthesis, amethod based on fermentative production and the like. Citrulline canalso be acquired by purchasing a commercially available product.

As an example of a method of chemically synthesizing citrulline, themethod described in J. Biol. Chem. 122, 477 (1938), J. Org. Chem. 6, 410(1941) can be mentioned.

As examples of methods of producing L-citrulline by fermentation, themethods described in JP-A-SHO-53-075387 and JP-A-SHO-63-068091 can bementioned.

L-citrulline and D-citrulline can also be purchased from Sigma-AldrichCorporation and the like.

In the present invention, a salt of citrulline may be used in place ofcitrulline.

As salts of citrulline, acid addition salts, metal salts, ammoniumsalts, organic amine addition salts, amino acid addition salts and thelike can be mentioned.

As acid addition salts, inorganic acid salts such as hydrochlorides,sulfates, nitrates, and phosphates, and organic acid salts such asacetates, maleates, fumarates, citrates, malates, lactates,α-ketoglutarates, gluconates, caprylates, adipates, succinates,tartrates, and ascorbates can be mentioned.

As metal salts, alkali metal salts such as sodium salts and potassiumsalts, alkaline earth metal salts such as magnesium salts and calciumsalts, aluminum salts, zinc salts and the like can be mentioned.

As ammonium salts, salts of ammonium, tetramethylammonium and the likecan be mentioned.

As organic amine addition salts, salts of morpholine, piperidine and thelike can be mentioned.

As amino acid addition salts, salts of glycine, phenylalanine, lysine,aspartic acid, glutamic acid and the like can be mentioned.

Of the above-described salts of citrulline, citrates and malates arepreferably used; other salts, or 2 or more salts, may be used incombination as appropriate.

The beverage of the present invention can be produced by an ordinarymethod of beverage production except that citrulline and citric acid, aswell as sodium citrate or disodium hydrogen phosphate, are contained.

The beverage of the present invention may be supplemented withsaccharides, souring agents, preservatives such as antioxidants,colorants, flavoring agents, and other various additives for use inordinary beverages. With the expectation for enhancement of healthfunction, vitamins, minerals, and various functional ingredients may beadded. Carbon dioxide may be pressed in to obtain a carbonated beverage.

The saccharides are not particularly limited, as far as they are usablefor producing a beverage; any of monosaccharides, disaccharides,oligosaccharides, polysaccharides, sugar alcohols, and sweeteners isacceptable. As examples of the saccharides, glucose, fructose, sucrose,maltose, trehalose, xylitol, erythritol, reduced glucose syrup, dextrin,starch, sorbitol, maltitol, sucralose, aspartame, acesulfame K, stevia,saccharin sodium, dipotassium glycyrrhizinate, and thaumatin can bementioned, with preference given to glucose, fructose, and sucrose.

The souring agents are not particularly limited, as far as they areusable for producing a beverage; examples include tartaric acid andmalic acid.

The antioxidants are not particularly limited, as far as they are usablefor beverages; examples include tocopherol, ascorbic acid, cysteinehydrochloride, and L-ascorbic acid stearic acid ester.

The colorants are not particularly limited, as far as they are usablefor beverages; examples include Food Color Yellow No. 5, Food Color RedNo. 2, Food Color Blue No. 2, carotenoid pigment, and tomato pigment.

The flavoring agents are not particularly limited, as far as they areusable for beverages; examples include lemon flavor, lemon-lime flavor,grapefruit flavor, and apple flavor.

The pH of the beverage of the present invention is normally 2 to 7,preferably 3 to 7, particularly preferably 3 to 6; the pH of thebeverage is adjusted with pH regulators such as organic acids andinorganic acids.

The organic acids and inorganic acids are not particularly limited, asfar as they are usable for producing a beverage. In place of organicacids and inorganic acids, salts thereof may be used. The salts oforganic acids and inorganic acids are not particularly limited, as faras they are usable for producing a beverage.

The concentration of citrulline contained in the beverage of the presentinvention is normally 0.01 to 2% by weight, preferably 0.05 to 2% byweight, more preferably 0.1 to 2% by weight.

When sodium citrate is used in the beverage of the present invention,the blending ratio by weight of citric acid and sodium citrate containedin the beverage is normally 5:1 to 1:6, preferably 4:1 to 1:5, morepreferably 3:1 to 1:4. The combined concentration of citric acid andsodium citrate is normally 0.01 to 3% by weight, preferably 0.05 to 2%by weight, more preferably 0.1 to 1% by weight. In the foregoing case,the citric acid ion concentration in the beverage is normally 0.0078 to2.9% by weight, preferably 0.039 to 1.9% by weight, more preferably0.078 to 0.95% by weight.

When disodium hydrogen phosphate is used in the beverage of the presentinvention, the blending ratio by weight of citric acid and disodiumhydrogen phosphate contained in the beverage is normally 3:1 to 1:5,preferably 2:1 to 1:4, more preferably 1:1 to 1:3. The combinedconcentration of citric acid and disodium hydrogen phosphate is normally0.01 to 4% by weight, preferably 0.05 to 3% by weight, more preferably0.1 to 2% by weight.

In the present invention, when a citrulline citrate is used in place ofcitrulline, for example, the citric acid includes citric acid derivedfrom a citrulline citrate.

By allowing citrulline, citric acid, sodium citrate or disodium hydrogenphosphate to be present in the beverage at the aforementionedconcentrations, it is possible to provide an easy-to-drink beveragewherein the generation of bad odors due to storage or heating issuppressed.

Hereinafter, test examples are shown in which bad odor suppressingeffects in the citrulline-containing beverage of the present inventionwere examined.

TEST EXAMPLE 1 Bad Odor Suppressing Effects of Citric Acid and SodiumCitrate

Each of the beverages of Examples 1 and 2 and Comparative Example 1 wasplaced in a covered bottle and heated at 120° C. for 20 minutes, afterwhich a sensory evaluation test was performed by six subjects. Ratingswere made in comparison with the bad odor produced in ComparativeExample 1, using the evaluation criteria: 1; effective in deodorization,2; slightly effective in deodorization, 3; little effective indeodorization, 4; ineffective in deodorization. The results are shown inTable 1.

TABLE 1 Mean value of evaluation Example 1 1.8 Example 2 1.3

From Table 1, it is evident that with the beverages of Examples 1 and 2,which contained citric acid and sodium citrate, a definite deodoranteffect was obtained.

TEST EXAMPLE 2 Bad Odor Suppressing Effects of Citric Acid and DisodiumHydrogen Phosphate

Each of the beverages of Examples 3 and 4 and Comparative Example 1 wasplaced in a covered bottle and heated at 120° C. for 20 minutes, afterwhich a sensory evaluation test was performed by five subjects. Ratingswere made in comparison with the bad odor produced in ComparativeExample 1 using the evaluation criteria: 1; effective in deodorization,2; slightly effective in deodorization, 3; little effective indeodorization, 4; ineffective in deodorization. The results are shown inTable 2.

TABLE 2 Mean value of evaluation Example 3 1.5 Example 4 1.4

From Table 2, it is evident that with the beverages of Examples 3 and 4,which contained citric acid and disodium hydrogen phosphate, a definitedeodorant effect was obtained.

Hereinafter, examples of the present invention are shown.

Example 1

Citrulline-Containing Beverage (1)

Ingredient Amount (g)

L-citrulline (manufactured by Kyowa Hakko Kogyo) 1.00 Citric acid(manufactured by Kishida Chemical) 0.75 Sodium citrate (manufactured byKishida Chemical) 0.25

These ingredients were dissolved in ultrapure water to make a totalvolume of 100 ml.

Example 2

Citrulline-Containing Beverage (2)

Ingredient Amount (g)

L-citrulline (manufactured by Kyowa Hakko Kogyo) 1.00 Citric acid(manufactured by Kishida Chemical) 0.20 Sodium citrate (manufactured byKishida Chemical) 0.80

These ingredients were dissolved in ultrapure water to make a totalvolume of 100 ml.

Example 3

Citrulline-Containing Beverage (3)

Ingredient Amount (g)

L-citrulline (manufactured by Kyowa Hakko Kogyo) 1.00 Citric acid(manufactured by Kishida Chemical) 1.00 Disodium hydrogen phosphate(manufactured by Wako Pure 1.00 Chemical Industries)

These ingredients were dissolved in ultrapure water to make a totalvolume of 100 ml.

Example 4

Citrulline-Containing Beverage (4)

Ingredient Amount (g)

L-citrulline (manufactured by Kyowa Hakko Kogyo) 1.00 Citric acid(manufactured by Kishida Chemical) 0.50 Disodium hydrogen phosphate(manufactured by Wako Pure 1.50 Chemical Industries)

These ingredients were dissolved in ultrapure water to make a totalvolume of 100 ml.

COMPARATIVE EXAMPLE 1

A beverage containing 1% by weight of L-citrulline in ultrapure waterwas prepared.

INDUSTRIAL APPLICABILITY

According to the present invention, it is possible to provide aneasy-to-drink beverage that contains citrulline, wherein the generationof bad odors due to storage or heating is suppressed.

The invention claimed is:
 1. A beverage consisting of (a) 0.01-1.0% byweight citrulline, (b) citric acid, (c) disodium hydrogen phosphate, (d)water, and (e) one or more supplements selected from saccharides,souring agents, preservatives, colorants, flavoring agents, functionalingredients, and carbon dioxide, wherein the saccharides are selectedfrom glucose, fructose, sucrose, maltose, trehalose, xylitol,erythritol, reduced glucose syrup, dextrin, starch, sorbitol, maltitol,sucralose, aspartame, acesulfame K, stevia, saccharin sodium,dipotassium glycyrrhizinate, and thaumatin, the blending ratio by weightof citric acid and disodium hydrogen phosphate is 1:1 to 1:3, and thecombined concentration of citric acid and disodium hydrogen phosphate is0.01-2% by weight.
 2. The beverage according to claim 1, wherein the pHis 2 to
 7. 3. The beverage of claim 1, wherein the beverage contains oneor more functional ingredients selected from the group consisting ofvitamins and minerals.
 4. The beverage according to claim 3, wherein thepH is 2 to 7.